Trigger an event when focus changes

[sindresorhus]

I imagine it would be something like:

const activeWin  = require('active-win');

activeWin.on('change', win => {
    console.log(win.title);
});

With win being the same as activeWin() returns.

No idea how to achieve this though as it would have to communicate with the binary somehow. Maybe spawn the native binary when someone subscribes to the events, and have the binary push to stdout for each event.

PR welcome 😀

[bencevans]

Not ideal but I ended up polling and emitting an event if the data changed from the previously cached data... https://github.com/bencevans/active-app-watcher#readme

[bencevans]

Python implementation https://stackoverflow.com/questions/23786289/how-to-correctly-detect-application-name-when-changing-focus-event-occurs-with for linux using xlib

[sindresorhus]

Some more resources:

• https://github.com/seanhess/VIntage/blob/master/FocusObserver.m
• https://developer.apple.com/reference/coregraphics/cgscreenrefreshcallback
• https://stackoverflow.com/questions/347396/how-can-i-use-cocoas-accessibility-api-to-detect-that-a-window-is-brought-to-fr
• https://stackoverflow.com/questions/853833/how-can-my-app-detect-a-change-to-another-apps-window

[Pandakls]

That kind of event emitter would be awesome.

[sindresorhus]

@Pandakls Your comment doesn't add anything to the conversation. In the future, please use GitHub reactions instead.